package cn.tedu.sp06.fallback;

import cn.tedu.web.util.JsonResult;
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.stereotype.Component;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;

@Component
public class ItemFB implements FallbackProvider {
    //针对哪个服务应用当前降级类
    //返回一个服务id或者"*"/null对所有服务降级
    @Override
    public String getRoute() {
        return "item-service";
    }
    //返回的降级相应 封装在response对象中
    //根据自己应用的需求，可以返回任意的响应数据
    @Override
    public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
        return new ClientHttpResponse() {
            @Override
            public HttpStatus getStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR;//500 internal error
            }

            @Override
            public int getRawStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.value(); //500
            }

            @Override
            public String getStatusText() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase(); //internal error
            }

            @Override
            public void close() {
                //ByteArrayInputStream是内存数组的流，不占用底层系统资源 不需要释放资源
            }

            @Override
            public InputStream getBody() throws IOException {
                // JsonResult----{code:500,msg:系统服务故障,data:null}
                String json = JsonResult.err().code(500).msg("系统服务故障").toString();
                //数组转流-----Json转数组
                return new ByteArrayInputStream(json.getBytes("UTF-8"));
            }

            @Override
            public HttpHeaders getHeaders() {
                HttpHeaders h = new HttpHeaders();
                h.add("Context-Type","application/json;charset=UTF-8");
                return h;
            }
        };
    }
}
